The present invention relates generally to the field of filtration assemblies. In its more preferred forms, the present invention relates to multiple tubular filter cartridges which are held together as a unit (xe2x80x9ccagedxe2x80x9d) in parallel relationship to one another between spaced-apart end plates, and to the filtration systems which employ the same.
Caged filter cartridge assemblies are known and have been employed conventionally in fluid-filtration assemblies. Conventional caged filter assemblies typically include an array comprised of a large number (e.g., eighteen) of generally tubular filter cartridges positioned parallel to one another between a pair of spaced-apart end plates. A tie rod extends generally centrally of the filter cartridge array and structurally unites the spaced-apart end plates to form an integral unit.
The integrity of the structural union between the end plates and the filter cartridges provided by the tie rod associated with conventional caged filter assemblies is problematic. Specifically, the tie rod does not impart sufficient torsional rigidity to the conventional caged filter cartridge assemblies. As a result, during shipment and/or handling, the filter cartridges may twist about the axis of the tie rod resulting in some of the seals being broken or damaged between individual ones of the filter cartridges and the end plates. Broken or damaged seals, of course, results in reduced filtration efficiencies during use.
An additional problem associated with conventional caged filter cartridges is potential xe2x80x9cdishingxe2x80x9d that may be imparted to the end plates by virtue of the tie rod being over-torqued during assembly. That is, there exists a real possibility that the axial compressive force on the end plates provided by the tie rod may be somewhat greater in the immediate vicinity of the tie rod and somewhat lesser at the peripheral annular edge regions of the plates. As a result, the area in the immediate vicinity of the centrally located tie rod may be recessed somewhat as compared to the peripheral annular edges of the plate, thereby resulting in a xe2x80x9cdishedxe2x80x9d appearance. Such xe2x80x9cdishingxe2x80x9d of the end plates can also lead to broken seals between individual ones of the filter cartridges and the end plates leading to ineffective filtration capabilities during use.
It would therefore be highly desirable if improved caged filter cartridge assemblies could be provided which exhibits increased torsional rigidity without xe2x80x9cdishingxe2x80x9d the end plates and thereby maintain reliable seals between the individual filter cartridges and such end plates. It is toward providing such improved caged filter cartridge assemblies that the present invention is directed.
Broadly, the present invention is embodied in tie rod-less caged filter cartridge assemblies wherein the structural integrity of the assembly is provided solely by means of the individual filter cartridges. More specifically, according to the present invention, the end plates of the filter cartridge assembly are provided with plural seat recesses each adapted to receive an end portion of a respective filter cartridge. An annular lock ring is associated with each seat recess so as to immovably lock the filter cartridge ends therewithin. In such a manner, each of the individual filter cartridges serves to structurally unite the opposed spaced-apart end plates one to another in the absence of a tie rod so that the collective torsional and longitudinal rigidity of the assembly is significantly enhanced as compared to conventional tie rod assemblies.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.